کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1287819 | 1497996 | 2013 | 8 صفحه PDF | دانلود رایگان |
It is well-established that the micro-sized LiFePO4 exhibits very poor rate capability, whereas nano-sized LiFePO4 displays very excellent rate capability. Thereby, kinetic behavior of nano-sized LiFePO4 is attracting wide attention. Herein, it is reported that nano-sized LiFePO4 can realize the fast charge/discharge of 100 C with limited carbon additive. Most importantly, it is discovered that the capacity of LiFePO4 observed above 3.5 V (vs. Li/Li+) and below 3.4 V (vs. Li/Li+) is mainly due to the pseudo-capacitive behavior rather than single-phase Li-intercalation, indicating that there is only very small potential difference (100 mV, 3.4–3.5 V) between the single-phase transformation and two-phase equilibrium. Also cycle-life test, combining with TEM observations, demonstrates that the crystalline-to-amorphous transformation in part of nano-LiFePO4 particles during cycling process can result in the change of voltage at the end of charge/discharge.
► Nano-LiFePO4 achieved a capacity of 80 mAh g−1 at a discharge rate of 100 C with limited carbon additive.
► Capacity of LiFePO4 observed above 3.5 V and below 3.4 V is mainly due to the pseudo-capacitive behavior.
► Crystalline-to-amorphous transformations occur on the long-time cycling process of LiFePO4.
Journal: Journal of Power Sources - Volume 236, 15 August 2013, Pages 230–237